We've heard these stories before - The serious accusations of rampant child sexual abuse triggered the NT Intervention, which was later to be proven untrue. If the abuse is true, why are the perpetrators allowed to remain in the community, and if untrue, the WA Commissioner of Police should personally apologise to every Homeland community.

The West Australian Police Commissioner must explain where he sourced statistics used to support claims of widespread sexual abuse in remote Indigenous communities, the Opposition says.

The Opposition's Aboriginal affairs spokesman Ben Wyatt told Parliament the figures were used in a newspaper opinion piece authored by the Police Commissioner Karl O'Callaghan in March.

In it, Mr O'Callaghan backed claims by Premier Colin Barnett of sexual abuse in remote Indigenous communities, quoting statistics from an unnamed publication from the Federal Government's Australian Institute of Family Studies.

Mr Wyatt said the Commissioner claimed the institute had found 88 per cent of child sexual abuse in Indigenous communities went unreported, and that installing contraceptive devices in girls as young as 12 was "not uncommon".

Mr Wyatt wrote to the Police Commissioner seeking the source of the figures, but last night told Parliament he was simply referred to the Police Minister.

"In line with current ministerial protocols, any contact by a member of Parliament with a government agency, should be referred through the appropriate minister," the Commissioner's staff wrote in response to Mr Wyatt.

"This policy ensures that ministers are kept informed of issues relating to their portfolios."

Mr Wyatt said the Commissioner entered the debate on remote communities and should explain the source of his claims.

"If he's going to quote statistics in the public debate, [then] go on radio to talk about those statistics in the public debate, then he's got to expect questions from those people engaged in that public debate," he said.

"I don't accept this position that the Police Commissioner has taken hiding behind the coat-tails of the Police Minister."

Mr Wyatt said he had reviewed documents on the AIFS website and had been unable to find the source of the claims about unreported abuse.

His own checks also failed to verify the claim about it being "not uncommon" for contraceptive devices to be used by girls as young as 12.

Mr Wyatt said he raised the claim with doctors and medical staff in the Kimberley.

"No one seemed to know ... it's effectively a procedure," he said.

"It can't just happen without documentation or statistics being compiled.

"No one can provide me with any information about this."

He also said he spoke with long-term sexual health workers in the Kimberley.

"One of them was aware of one [case] and [Department of Child Protection] were involved with that," he said.